SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2387512fa24792d3a6081285dc92e72abd880cd6eb1f5ace13b7aee6189a9679' 
  AND token = 'gUS/6qhC2hqXKhIuHfvQeKrCOrqM+WT092LlOStIzV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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