SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6db21178da0d72cc62d2d3ba32e3963f89e97c58cff5de42275a3bb0564362f' 
  AND token = 'RWjQxd9p6Y04URecLu7wzHB6QlanbX7O+WbQG/+7nOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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