SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56eb9b2358ccc82482b34a5b8ac6ab39846f0b8f279baf74c45d01b2104fbfb1' 
  AND token = 'Vu1+KtKNXDDkfjvjALNSgRzyYa6d5zLaZzChhO+0hrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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