SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98aa52afcb4644e8565f4385ffcf97711d27721d598b2c171e094407fb824f80' 
  AND token = 'wY6pcYjwSuggpHpOBGRIfHPPPPm16prMEd1c2p3wKDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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