SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0de52bfbb0aceb0effa403b6f2a06894971b2556a857a8fd557c576af601f1fd' 
  AND token = 'MHm3B2NS+cOkhXvIkywNjL/9RlwjXpYkuDyJGbDKXHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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