SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aad9d32a5a26be7d556bfef4bc05fa0ffbfbfec74c4df309b2795af3ec2ffa87' 
  AND token = '6LGDYb8Cx5Gvrz63ijavsnOUBKfE5Nm8SCcHOTwaHAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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