SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cddeeabb164d9ec7b6e750466d8ca719ea16123f63f72555284d06b874d40635' 
  AND token = 'HfyfH+EN6DTNNOOgN40W6A58aQXt3tio5sQTcJqJefw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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