SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24375a1c729e5bbce0606f675d98f5922a21b0c1d1bcd9dd10a45a30bc57384b' 
  AND token = 'FuXI0uco3DI+SF2YjvNHGGY9ZJlluJ6fzqFMf/uBkRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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