SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '566f815de0079fc4a14857c4a147ff35f898e0f4c5871aabab4bce64be80f609' 
  AND token = '3aoq/rjLHlAB30jIGAq8tvtuRGr58bJ5uqDwbWb5lPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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