SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e23b69b732945a220a5fd9d61fa32fa6ab82c2a584f707fcd02212e0d09c8b9' 
  AND token = 'oUxPqY9JsApewopIbqEzFgtaqmqlF57bxmlosjon+2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}