SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a4af2e94f21cb1ace9be271f7e739a7c57a05b7ec7cf48036a654b852587add' 
  AND token = '3zoYTFGp/HUdTSyCOnMenUpSPtNrXp70IAI4FGbBDaY=' 
  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"
    }
  }
}