SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0eb3f07bac26031175bf0dbf61a67664502517c7610069a3c9d4e56de6d8a81' 
  AND token = 'AeT/8g8pWlTXRlCWSNTeJ6eCV//tsNtQPWCh+QkFjuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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