SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94ccc754537106bb65574661e63097fb9caced0096c6e0c31d52223d2f9bd7e8' 
  AND token = 'ePIsANHTd5Oe/5Rw2/sE1E51x6cYU7+br6BwO8T8ORs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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