SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3367bef347220c2ad18cc051f01c816fe3018689c44db67e46e8caaa7f41f80c' 
  AND token = 'L2XGU9bKuhI2zFbRX5aONhCyUAzS3p2IQ/zMnBQUgUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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