SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f53ad16f320e31d24b4939c856e18ccb34f22b8a3d4dccb03230162ffd9e571b' 
  AND token = 'z0O0Ivcbega2NtA4OUTuZwTWM5V7pmBGRIdzHjlTTFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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