SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8cd9d6b450629dff02ef5cfc1178750329c64ca0611dd437493ef2b1dafee94' 
  AND token = '7jV9UvgB/fNwr0sIOhPSbQNTd83exQpLnb+WB7XHjq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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