SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96f3e70ba5f8870c5878d9f6741f64aa5769159a7bbc9e73129159c7987630e1' 
  AND token = '0aUiwmX3Hv0QxoCeQXEEve+raib5a6ZzVnuXo3/d7dQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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