SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '556cde715e3370b99be42977f76684a7e988c098ce359a5647d5536bce26604d' 
  AND token = 'gm5fuAwMX5Jo71ikYPnZKMbYizgRuWXQDkeqXy/pt+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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