Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f50e39ff0c19d6079d554556bc6d7f730f825a89a96faad0616ea992fa3e16f' 
  AND token = 'ZQ6EhcXx/+7jzmRQD6eDi4P2BF8VpvSKdFkRO0JXQWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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