SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4511d1462ac603a94f4c58e688f7f21c7545fc9123366dc875f080cc8bdd2539' 
  AND token = 'vDRB5TJ6Z4SWypvjOYsj1KC0YvoS/0VxgXSOy5KbzCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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