SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a4003ce6c37c31c533b71fb1f8a0c4fd50b4176805959901f48f8be34ff3437' 
  AND token = 'VcJkXB/qffhByp/t499YRLUGKKnErV1qtMrFMUHtgu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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