SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5696511f5cdea3615e7596f4e83bded17e66a9dfc828c98efb0b98e71945ced5' 
  AND token = 'C8TSVArQpLxT9Iv0YRmDrwVKEv5vzFPk2qAyk9pIMZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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