SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ff4df828bb547979b9cafbffbbfe3ecdf7775be7199a170cc40ae41d8f91179' 
  AND token = 'ntwNGWUhVuyBVUy0uy64bggiNIziCRMqPQxjsbiQfvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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