SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b194f9e63d5af7fcf64bf7b4181fa548c7ff85528edc527e0d8dc4dde953f5d1' 
  AND token = 'QJeL79HJknpw2V9TFMl4eLo2orKbv6Z+aJc7Xu26pY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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