SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01212f96ee2ba325729f66da8fd376978e1e545d42f4ddf52698bab7d8bce9e9' 
  AND token = '7bCtnXJX7/R7kvY2jGMKGMKAnXWVHBKDZJf5ccUwquA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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