SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e387adb90c33ec5108ef90a6f6ce238edac1684f72b036e5b2b31c4a10979f3b' 
  AND token = 'jvCDzH3V/P/8mqnjERZ3m0jlXfWgHHG5rG97C8JWfHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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