SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f479340b959162aae6d9d7fa597f64c90ed727fff651e6d40d662c0041593508' 
  AND token = 'hLqPrxxiZzTIQUCLYQr9yPplQnASMOuVIc7t2vc4yp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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