SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1725c401886732d1332383ee9033034a0ec9e0cf9da009002f941fcc1713aafe' 
  AND token = '5p7X6i9NZmagAMioDe7MGp0NsZPzcXhTbEgd5PNmcDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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