SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e97ebba6788404b720eeed1eeeee0455369cf820ad3e7e5795d06c397e716cc' 
  AND token = 'DqoK+jtsLbQKetCadKWqjBS5Rw7L4oe+8WICs94+D1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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