SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ddc1941618a2065b895d019637be0ddfe862a2bdcb1135c201b54b40cc3ac38' 
  AND token = 'tQkmEpRapV0dPkdbUIt5tTUcq7JC8qya9wX4Z/URrKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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