SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '974e2f07a665185284156e3a897a537fd3c82a4c79d54e04cc2da4bd169781d7' 
  AND token = 'GnM/7a+xELzBKd81aLrINYG4tfl4SyLg/HUSY/aSAb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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