SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd2c40851f6adfdc53acb9afc0522d249b8628b382113bc4124f0cfd518ed7dcb' 
  AND token = 'RB9NiwkPBnGE31iszNMtHJNaP5pMRV/awZnTmVnQ53U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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