SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82e2ba4f13e6938015714a4e4e6b4613af7d22bfb1ec1f5db3682656104fa8b6' 
  AND token = 'VksjzcsBFp6dwaupsvK4mxqhMbPPn6O9qcrTD/zYR1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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