SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c7bfb33d3ae0e637d0085c266c8f26b3f402dab0644b68861329de728d10719' 
  AND token = 'VgZnKdbZVQ1jRv49LFqwptSLVFbsAPTemMPLwogJpUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}