SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f2630de0dbe7b86191087eed5e18a8979ec145b736c9f53613b8782ca3d51b7' 
  AND token = 'UMwCGHnDP1mtZQV7k2mA4seQSOIresjfkzRpeJOCbQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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