SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ad4814c18add080c57341ddbc67f04e559e9796cd1debe5aff025cca61ca967' 
  AND token = '4gLRXTKTeJwuIs2riWrw1XmkrQOP4roYtDqgaPrEDOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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