SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fede1a795fbe8ce1601764d22747173caaca744306149bc9158268b1a3308c79' 
  AND token = 'RnQrd3XohxKGHWJNBtpO2WXI3xgwo+Fb5Sw5/4sP7hY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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