SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a030f01edf182f4b46c047d21e1d145e25e3dc6a453e27aa4a92ebc082e94763' 
  AND token = 'YYYWMPbzLjRUgoreVd+WZNtBfDK0sgaxmrLZ9hbkArs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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