SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30eab48165a1833f3dcae51f40a2f16b6fe705cb17b83d29ed6cc20d0ffe656c' 
  AND token = 'j9XfgLZ+koSwrsgPwNbq6IiKAUKQdvTYPkkw4zcrCrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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