SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82b576463383e190060d9c28b7d5077f3ad52867be428a47f3fef9c9043cb9f9' 
  AND token = 'blrWjUl3pWWn6Agf/W7O7YCEZVyGxLxKZW6DZJ7zsxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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