SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a6f5a8b3c6ec892981514b69804db8e7af8fa37f6a4a559590ecbdfae3d8bce' 
  AND token = '8RvUIw9YsKaj7PhqXBTPUZHFR4OnxVV1Y36JPD1sY9c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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