SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55b48680c2f6f23a56d79ab87a09bb17d2eac4ada032be68289c9c6ed98ccd11' 
  AND token = 'K7kmNPLiqjuDztO3pCWXmS/R/CGqSSgSVJisqEhNsoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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