SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '314ca6af474426185b2039e66e510854533355c01aebe76cb5cb3980fe34e58b' 
  AND token = 'DRkkkpUUXxBbabN5ErYEZNW2k8z2k2Sq9wRw7L0sDZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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