SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03147b5253c564bd5c84724f272aa57c6a2665904392cba6da4dfd0bc9fd0b79' 
  AND token = 'XilfWWK2NlYuKfKxBadxbi7ZFyO5bdkzoGGNSyzs9ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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