SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c949bd68707900947e8fb1ec4d0c0c376b057fbae654c3161bf45cc3c4665929' 
  AND token = '9H+TqTcz5lPnu0uHjwYhzhgb5nwlUEVEhgC1MKGAj2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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