SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c33ab74ac5242ae048dd04ae3409288e1c88b36be35c61bdc0711ac0bdc9a9b' 
  AND token = '0Ij1wfAntOwyIXoQk+tk8mZM725Wn9qdpOxQ9GeuAW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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