SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6bade5f990786948fe9d745f76339456803b62b2ffed4d41babff2d228acd33' 
  AND token = 'yXhsMke/yGpIVzx1S5MOWLEl2rYFYnPKZn3UplsnuQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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