SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bda163af82058a6917e0c9fa98ddc74e5ebd5790e083f31896f5186af776bc1' 
  AND token = 'Adv2tmTYB+SK8Atigj3sln6xkkJkpfuVu49ALFpMu48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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