SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1c05865d21ec47b13ca15b806d346cc5f4d93c74a9ae91798d715b6e8a18c52' 
  AND token = 'CYajvUTmsJjPyI7KXEKqzPvg6+RCrwSvIbz7AAIquq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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