Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c79c1e6c5dac2f5c188ef331708e15710065e125738a5e2abf2728d1b4a8f06c' 
  AND token = 's8NtEmVhvtHBYE7rXnJtdzTKngIjfzCWTBRGBmUtETE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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