SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '230042b388b68f061f5ae2b88d45727f72abc11b4aee27f2d9d0be51c2c80ba8' 
  AND token = '7cpiNpkujYmQZ1MY9/vnKmigsAsMxE0J8G6PZm0jRHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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