SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd8622134f3b16e68d6bf5751c5213a477a3e67b0f83436d4511fbc706499115' 
  AND token = '6D/v5cTA/vEPq03bti0NryCaOhj5n9A3HqrXwLzVvgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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