SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ece0090fe4da261c3838758b0bbec123158c5c09e4ba609894f2b257a4673fba' 
  AND token = 'irAvsjPjBflNEAq5/aVXjIIblclWIJCa0GEqgUkpTCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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