SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69877ee2aeb4bf8612d202168f30dab4ab89c43a472e8a707955a90f399ffc54' 
  AND token = 'tgsLUpjC3aywl+cwoBcOxCe//1dnPn6NLsHYBQvIM1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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