SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8adbecd0adc92ae01cf7dddeb5597ab5789cf5bf1092ee245e4a35daef3530ea' 
  AND token = '9RbFtVzv59Jn31FC+JLM5J7hikrdkNXwTn/Xfn4Yn28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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