SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad3e74a6ac67526089b74209eaba17c841ad6ae9c7ea1ed95877ce6fb45978b0' 
  AND token = 'INZ+hJeJ6fDCGhQMOfzGfCQeENxdAsGJOlavCaddv7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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