SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '049de83834d064519e31d634b69bba4b31c55089479989deb9638ad38fb2830d' 
  AND token = '5p8H4qgzuWCvsff8koKNbpPZD+Kn5UVxTE2yPoQKzYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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