SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '628abddb82c8066b6238fed39fb970d96601442a3148ecd8ccab18c566a316c1' 
  AND token = 'Ool0OqoEVLK306yQCB388soQaprY7XSNt9ZnQvdwh6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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