SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '579272d51700ee4aa2abd2589637eaaa4e5029d5a21191d3700e8647ae6807f2' 
  AND token = 'Z7Px3ECLrtOLwB0fcUnxiYuzsIGbfx78GtOv+gqNXwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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