SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b09d13cc33c96d68d145fc664789a9ae61bdff7c7fbaf753f1e8f9f88b017bc' 
  AND token = 'FLz3lwz+6KyusHRBymwKcJQHwWqSJgCQe2rpaEJIzE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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