SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f0bc4ab04be01f8ad44365c48155791a089c0bd6d7886d6f4e5daf3c7797f8b' 
  AND token = '93NhVjqZaBHSnXzZjRQ0vK+gTUnwHtb7BrWWP9MGQv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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