SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a583e6648a3a00e263ec44c96dbf9fd0501fefeeb787933a2b0ea41583b0a78' 
  AND token = 'sR+APXLrBzvj6S8oF24GLWvNlgqv0cZptwwLa24RPTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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