SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68ddba197b6641c306066113f0f1ecbda3ba2d93fdb81e7d5242617b8be71673' 
  AND token = '6pgupm3p/Y8JxAymHzra+YfNN4S6R14V+3USM7lw+ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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