SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47ac8345d43b21b75b179bd67b839f41b568a8eabfa835a637858dda1fb779bc' 
  AND token = 'JL77sAmDOHf8yT84OwK6a6Iu2kGLsTCfMQAYn1eVbkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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