SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef425f65bf5468fcca8f7ef31b5bffca717b3ea28afe9a4d942ca7e17577bbdc' 
  AND token = 'STPwUkgnIOqPDV16DjhL8T7YdHPqiLaOp6J6zmblKXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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