SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3eb4480e6fef613d4399717cc1c8ef3e35c1625f4f31799fd2c42b20c41a641b' 
  AND token = 'mzGZKhvFcOZduhL2ojpiVyqfBYpmOXsnj5KQjR9BSVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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