SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52ce71eaa66ff4576535a1d6aeb803c7375baa73a70ff522d05ebaa3acb72fe4' 
  AND token = 'XtnwUmfQpqxF9CT14v8UvuTjZnOtQNHw6L8ftSwh9u8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}