SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '567731af75b0723f6be269a53dbea4b7663fd06cbb334e9e53a3ec575a681e9a' 
  AND token = 'ptp4vbY/cGFZg0dp//yRHGwUPrQsFGSyskUgqztU1iM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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