SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d9d626942dd0ceae09d2f5729aa5d6378a9fb97830c66e633451c0feda8a01f' 
  AND token = 'wRKVGK+uALT41PZXMlRZHOZcvhUEgriueryLHAmo7Yg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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