SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '201b5e83dd62ea2275ba6412130942b64a89b1746cfd8e8cf8880ae0893574ed' 
  AND token = '8rEPDPAh7JCBGaWrOsK10ARHRVHixWN6z5gZqlXhPJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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