SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ed2b90abc53bd6c68b808fea7bd7eac63a2a9b1f401cbfb1a6cb7a5602630f7' 
  AND token = 'QlfwAGYRzq1xXCQDLfd7+jsfLekuRtsh3xkx0JKJoSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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