SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8375ee0c52ce92c1a1a98da22e00ee40ebc630a7c003e4fbbfedc111f00ae811' 
  AND token = 'cCpFYXGSba6COMwuvpJ8etqesPEeYI02CKLZZ3tgIDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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