SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4afe8d3ef68ce093d982625f7a87132f8fc8ddd71977d19a537d97db7117272d' 
  AND token = 'iWQz7py9QVdcANhl5T95j0L4uqw3tD3mLd32ClXenUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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