SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83de9a49a5ddc4246a08a1be3ea453745b8f23c821ff373c99aaa5b2aff93ecb' 
  AND token = 'ymEivHblait7CH2ymmCKonZQOX4ykO6wfzp0oyjzP+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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