SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd61f76766a95256b2affc7b990077fde2c92b8a9ad7b2fed815cb871c6cb43c' 
  AND token = 'cyl6IQRmARNTtyxfqjueqo9h783p4DZoH176ICiCjTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}