SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c6b6fc55eb40e275722a0740347095aca2a7398f6a563442daa0ae100d3feaf' 
  AND token = 'wdBhjQKXAGczBxxHWjeml8D2KY6IPg71bhx2TbOvjTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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