SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ab207dd98fb4dea8cb1065e831d88d06c6a49dbfc812c241e00e9f77cc8c461' 
  AND token = 'WD3qsdxfzVW0Go3XOvCWpvzVGec87BQxs49hZHzbCEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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