SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9feb252989b14c84ae49629a113402f587512e783aa7e4a56c71d2ecf1b06cc' 
  AND token = 'AhjiU1ZOymr9gHmah2TdM/4GLk/iDgNUM71YjXwetx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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