SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd706e8bfb158b6b75715625748ad6cbebde2f8fab3293ca0c6eb0322fec8191' 
  AND token = 'mKr8BBU3FgnpDAPI7T5jlax35yjIz261g/OJxj9cTfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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