SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5c2594f772d18a87af0f716ae123f625af9f79211d93a611f19472b264382f6' 
  AND token = 'yRWLJQjJsMXnS97NmdI34Ewkh+vp6hYhTY9jyzVROuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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