SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9652e1067b3b241c398fe38b186a3ff6c0441be9812a96d0115d4df2bf6afa8e' 
  AND token = 'LGxTjM8yvlCmvcVadb9OZPC1r1LK3ZiYMXC3MQkymro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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