SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '65a528564ee3499af06a6369943c975386bc3d8efdb2ac9a46b043c22239b609' 
  AND token = '1RJ9+EgW83dbGGfYH+XUPW1WvZZJcAMlCqfnMzL8IPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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