SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2176fc50c4dfd15092d017cf96f7599fe678d84bbb43e12d7ab83a29a7c693dc' 
  AND token = 'UABh2zyKIrSKjagIZP7FlYhMzySfAZiAcuPS8BAlUwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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