SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '780efaae36ebe68639318e2224b8e293c00845b4c8c18c75d48dc99678175cff' 
  AND token = 'O6Wrf/tgzIIfDT8YBJ+KgwkHB/tq+xSpj8r72uH2jbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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