SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '207f421b12cb43301f483226d98c2d057a1301eb8c5f290628ad8518348810be' 
  AND token = 'aFKvXQeUzY8JJUP0AChzVcDvC+D3+fieIfQjmYu5kqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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