SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ddcfa30fe9d43708b57d4da364b228d337f73bc0dedad2ac44c54c03e37bd26' 
  AND token = 'iK4D3h3WDEkVx/6ThUpeH8TIPQgt/eyO5FXKWONwF6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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