SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4dd46a1905baf2123fa65d93c972b761328acbc36ac9c058f40f992aae638c6' 
  AND token = '4je0mAi2fSuWzZGz2VATrJd71Ga0fIhcOmFJZN33FIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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