SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '81ebe1d8432732b97d1fd0a847aae508f180a73d33533b99c6e931006c68b00e' 
  AND token = 'ezoKuDsr0gLN3IjvnwMGBYqM3Jyz0Tv84SG8t1/33nQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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