SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95cef3f15aeac17f1b69412bcaffea4f177996efd74991c1d0cb51520352be29' 
  AND token = 'tQEtGIxG+Rvq4ab9FcllXVXDLfLCw1Rctju/1KBlw1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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