SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16f23867029d29589d83e6aed2c244d9f66dce6913a6ce842929efbaa48ba20c' 
  AND token = '43oQxGZhQM8jOzuCvpC0Z35G1g9+EKRjvOJN/LILcbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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