SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b9b4a61447629583bfc15c427e2e95e23ccaff7e58437294a5e7967e082230c' 
  AND token = 'GZyPaEoLG9dad196mg9hzUQTaLxFhwN2YT+o7koU31A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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