SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c600f3eb6fd04fcbc0422f31d6bcca0fa65fc77177d9f5744b1a906f8b8e02df' 
  AND token = 'WRSowDQ2lk/D2c9lCId4O3cS0z3pzpaTcA4pPZ7CJaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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