SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05db72bdb790b16d6a234146b927dcd99e5f81624e6a375cb3379a0a7cc17b6f' 
  AND token = 'ax76uHlvgGSSKer8QYaULhNxS4AZZyI/PDQAXGCBzyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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