SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ce6323f1b6e94c37472ff29e6c64ee5074ee27e1f890f7c7b0982324d0299ff8' 
  AND token = 'b5XDW9yKh9btYccj0GFio2x/YgP1/KqMpvOZct3BCmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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