SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3ccab5a33694aeb6d36847ed354715d6bd017a17239cfe0c44fc3a46f92bd863' 
  AND token = 'ou8K1/V/eLwFi7XllqHhEXxmFZOkg/j3uaY9bvrC504=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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