SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5caddfc2532c77adb28fc74ec29049c931c0438283598de654429d0433a9b29' 
  AND token = '4JuG3ZnL9cg7DHQyqNYNFFLk1WZzTTz+kqZiGgG9Rig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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