SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bb6f35d221c7423fbafa058175b2b8125e8aa143c30788a83ed98005c2c0ed0' 
  AND token = 'P0z8MHOse/hkrnscjksyOjqJQa2N6cRQe7oTVzyTaAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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