SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afeab68ad2d66c556aab63e420b9f092a10b705731df32cd6c90033e82b8281a' 
  AND token = 'ZRUQMU/rtmZD8t1j8pRTvqtdIosIxQ2FkzhkEnnUmKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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