SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '156f4e30ca813e0c36261f99d04bfbbc5acdbb1ef15240f29d47e2214f8ebf5d' 
  AND token = 'oVOJlyxU6LUdSRGzklTlIJ+XlIDwvm0n0y/FITgKrWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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