SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5d9a299884742c0d206d143867c10f3384b8bb959e95c139e48cce57810f8e64' 
  AND token = '21m+ITGkrZFOOwYadVEtGL1V2h+kLogYsYGoJqnW81c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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