SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0a776d527887e0ef7eb2537e9e9d71babab3bb07626f48daec10cad9757fa7a' 
  AND token = 'TzRj+8AhYDXqGSkffNfaumvjTYoWdJLb0VWQTidJzDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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