SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0a82532ec4a455df86c949eb75a6c9aa7f7931c75534054b3e2a3bee1727c6a' 
  AND token = 'egMPUFWJ+jmXv1AffEv9Cl8IACljMFn3frJkY0bQ4a4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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