SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94d54503ce40898ac1872edc2874a891fb762b2536518bfc498e22b31874e675' 
  AND token = 'iO1VgYxl3OOUMk0sbv5+CgpyfNGtw1DBozn5SE50I8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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