SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '204f972d58d927d1f2384c4860b6f7b15b44f01f0bbf5731a4d58cb560d95a5a' 
  AND token = 'M+aziTGRFm5Cvn9bf1d/GJkAgCDKWRc7LcSUBu0r6pQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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