SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3385f64f04ef0447e4fdc64f36e878c9ddde4510ff9b06749874927717368aca' 
  AND token = 'D5Qa26MIWzWFQL1nTxgAYcI3ftMoDSZgFbOPpthFnyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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