SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ce609d7232857c9d11c1de65d07f3d962814c6787882315bfff485e80ef8c6a' 
  AND token = 'toAxrzhxJZklPPxQ+gnqKDba3EgP1/VJhLt6715hZ3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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