SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94b08efb1f7967deb41056340b210829147392025b6e4bec623aee1a118345b6' 
  AND token = 'eCcR0tsKIU0U8rzNdxxqUfOLtCKgJXxq/xiZDCklWjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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