SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '465675ca17f06d10ad3c1e6c71840d114d3633159551f7619961c75cd4fae82f' 
  AND token = 'b9KXojzmhwVqC+saLTidqHN3RkLfEiWu8ALqdeEo60g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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