SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edc23571e1fc32621602b07be80e4156542cbcfa661376fe75560eecdd685415' 
  AND token = 'VL7alpB/BadlltVf1OoemT7WNFCMFS+8c9ntzLnrLQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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