SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65f71a515672489024f4f56b3a8fc6f52dcc98fcffbf7af83015055b8c6b56e9' 
  AND token = 'KGL8rNOGYbOkTiLpwwau8BorSdaKqE/kDujAvW0bDVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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