SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd9924763d2d252bd344ce9d7e8b88640f680826019c79957d8c0b7ec19fb59' 
  AND token = 'QqrUxOw6BhPivpgBMiOYHjW2gtZLFDIRtV1U/hWtXws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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