SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d49c69525926534b09f124fdd0c3f8c16de81af9d40f32377ebd2714232d4cb' 
  AND token = 'fn/wiHLUzPZZv7MYOGJgjfcPlsE55IoIADx+BY1RwNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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