SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c42858cc39aac996c3ae90086ba010cc7e7e248c2bc20e340bd6be199545506' 
  AND token = 'Buo5T+X4vSESUYZO1zRzDQO3vntuSPZo/Y6rqfiiexg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}