SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c7c6af45b32d76c532ac070b000abcd9f94ad49a916b8a417ae0fdb0d6f9319' 
  AND token = '3u9zJsmeIcdXVl5rPWJ+ZNU/Lei8rITfHi7+eYq+l1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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