SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4924763ffc16dcd834a20d6f9ae92a5eff3a79de5e4e4f41cfccbea381fb038' 
  AND token = 'sOMCLOwSJwkFbUQXxXBjwjpVnudOilrIA7zc4Wyksjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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