SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95aac53bafb96ee3ae655951100df39d9aa058f989efc7b166e901633daeff30' 
  AND token = 'S3mwGOwiV3c/31RwUlEBAU9xfZEILHmzKuP9VFT2E8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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