SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae623dc46e4467574064aa1c3d236c428dd9d8d2103feb810969c5c3e6122b9a' 
  AND token = '3pJQFhgC594eHvkmyaTytwFbHgZGXt/zKNWJCQIO3Kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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