SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03f1d366363e3ad8efcd6cb176bf61b2667c4973c1afdbbc135d28e532c7954c' 
  AND token = 'DUTuygzZXsGuFsC7Yyi3GiQ/QJjX7pOBN0UmlTtiHPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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