SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ea1a52e243fec950f717da368af711c687b5a6d6491514c941c05ad3108b907' 
  AND token = 'pt5szOR0SpgmknulAapkvGLhaHbV5ztl1PMdXAlRHyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00103

JSON explain

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