SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a43f40771019011bd0becd584d8f146fd652708c3046ea9572407ed6d528a8b2' 
  AND token = 'wGlePafFW25nGQoFMfSdbaPKE1LOJwhNgkKIPnVvn4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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