SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40c89f48e85f4689b6b86ef91826f49f51f87cd6398619de7b0c332f333b131e' 
  AND token = 'zJnRCGnMoZJM8LOWEWX8aHdl/H5D+QgG9V2KZQLWqXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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