SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63ff76189bc274af276d028c13b79c92a14808888f3c512a0e7d86174ca90c7d' 
  AND token = 'DfgvWzsZqhILa83uroLzfchUAxd4/WU28UPnAtpaf1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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