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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59e4f7ebb4fa521757f1c0df2cecb59e39dc84d3d07ca39a98a016314b619723' 
  AND token = 'UT0GzfMA+Bx0dtVankjgEPHl5QEzfsKRd6EN7PMRsPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}