SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2bcfe46e123313c901356f5b8327b888c410e9bb758eced37b016ac4b52ca04f' 
  AND token = '4P+ofvaA20BPo9FwE/8pezm2QPCTiCIbRxrKUMFX1mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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