SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71f4b286911ad47d85bed833c85222cdda00fccbbd4f852cb4cd7e112aed6b0d' 
  AND token = 'X8NtslmSKdp/dRZqjw49kOvG2+P+XG6LkOepOkJ5sDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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