SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4953c4f3f323595927bafbeb94c99a0626cb601ade31b7aaaa568657fe493eeb' 
  AND token = 'M/eXQ4HQU16N6pIl6Fsn6pC9VQ4ZNP8piYNC1bDn5jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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