SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fa61eac4fd3babfc53e86d8dda0cdbd19e63aeb183d78212580f891fa9acbb7c' 
  AND token = 'vmm7vPCZPgU9guoM1KHWQCjUn5oT/r3cbkMwm8gFSvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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