SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ac8be9225a77870b968efd94b2d5423c8e6478ad1ee227ab8b603e76b1c039a' 
  AND token = 'TDbJtVYdGThYPQYRGR4FmXh1trG9UX4WFM+A4ziUygA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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