SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b883ade0424c49a697fd3cea6754d5c2b3c36ca1574835f3d64fbf4861bf8ef4' 
  AND token = 'S7qKHmEVdS8oeSwjHwSI8CHb56n3FuyiHq8xYUy0t5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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