SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42d769cc7703310e538c9306623b28d77896196665896d62163c5cf327c56219' 
  AND token = 'hYAu/CqjEfh8MQ9BS4KJS9erFy6ql2zGyxpMgJBZtUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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