SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '365286044a62ae37ed203d8d5d2d1efa5cd9e116c1e8cf211d439b81fe9e8d77' 
  AND token = 'QOWzNzNwjQ3DcYtPsZ25uVD9X2NlLovHCh9CuNg/b7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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