SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dc946f255e79270e578f0b4cacce501fadc13893dd9cf3dd05e0eca59346e47' 
  AND token = 'vTMCWgtGDs/hrZzaorFwmwNqFfMl7xlhYWt4qs+tAw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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