SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bffa0723af868b7801652b33c3f834e477e9f97f00cfaa424f070eb9ac19aa75' 
  AND token = 'T/onQLQKzVdmPJxdXUTKwkfDaoFLgLIyHDZBsrvNyYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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