SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6156d33d8941b56d85c4b5f010c213e3d6f56a26a2a931052b171798dc75ee87' 
  AND token = 'UsqqHxTHxArZyhU7yalkjWnxWNW6rdPfsQ4xhVXNthg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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