SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbd170f4cadc16304b14c022e3881e7fd24e6565da663f05dd3a01a9d6612900' 
  AND token = 'cwc1hkVyKE7Wh3uiMJ9mKRf8zUomz0gqrXNT06i/NTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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