SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a826c63c1c79b0cbd08f54691325c2a5346de851995aaec90e4a6e114dcbf30a' 
  AND token = 'bkv5vNpb0szaqAsL9UJAmRuYZOukpNe69r2afqoEjBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}