SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c323f98708868949cb072904dd75fa8f65ab35f3d74e06ccfe896e7920ba097' 
  AND token = 'N33h0IUW6aZ06M0rJmhqTkTzZrV1ANlPAaplR2GTpNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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