SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7808dccfa6d46990a72b5ca2b2054f020c109ef2baaa875f4842f8a8f17a4fe' 
  AND token = 'f7Ypk3JqeJDaVCDUzkMjdjxQhurhamAXinqCwFXDtMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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