SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aa02c2cd34c0f181609e9e485c8c3f95b787cab65e56a8e60ac622a75f4b934' 
  AND token = 'U+g8h7zXcQbJYmR/QGtngP3iUTNy3ik9FGTKBZ/o/fQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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