SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd65d139884353c98a5c47e7cc7c51ffc4520e8ef471f957bfd1c73f2b1760b74' 
  AND token = '4PYb2wcUP7afkVhKtREA7aXSDsQx3okNBaKmOOyKvXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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