SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d54385f7ff48711c7866c6d3da2b3a0a977b855988e3111d1b78adbeefa50bd' 
  AND token = 'ro1W1QsKsCt7pXIVOphd/mBxd04sFrqCMSdjMAntXaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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