SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92c2a8e907ba8587a65478585e700c4feec1cc7bd0f7ca88d8154baf1200681e' 
  AND token = 'eEN28SItHNl4Z5gbqnnYyaQJrP0yEOCreXYoARyFyqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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