SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e9b8dd29df471d7d7f6a17b0ccb0e9e103aa134ee1ae8b95b72b432a07a5532' 
  AND token = 'wAB8ag/NarJwq4jSaFs1n9dQvB2cROhe72VK8hIszMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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