SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffeb81063ee54ede053ce890a8b61b8c9f9313387f8c59f0ba1655c5ea58a46c' 
  AND token = '8Xf99QfT0ubnoQkZM42cPRcWcM4h2qZ3QYjSjRXF19o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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