SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ee1425d3e5e02eedacd7420f0f5db7fe6de59d8b7ab171dea9fd25f0cb85071a' 
  AND token = 'zr2EA21dLoiX2Qu2/Qzzsn0mgRj5M3lUFJfWBAAKipg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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