SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '169fd805e44f689ec151e9e138c53cb420218276ece5a6bb525453c10b8adc86' 
  AND token = '35kNpP74UkwYnyq+ZSWXpYtWHKqpnthjTfCuDzOvBCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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