SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad9ad07c6a42177568e7ed6eb6ea09ec0babb371848958d317ca99f5b37c713' 
  AND token = 'fijofpIsRlYq7gqh/Kl1d3dZEK0Uqe8Rqz3zGlgfLMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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